It's exactly that: weird. Some of these lot really need to grow up.
You can even see it in Pogba's face, he's absolutely loving having Bruno there with him, and there isn't a hint of jealousy with him. Likewise, Bruno is enjoying having one of the most complete midfielders in world football supplying him with the ball. Both are spurring each other on to better and better performances. Likewise Martial and Rashford. None of them care who scores, as long as the team is doing well.
Add Mason (and hopefully Sancho) to the mix and it's got the potential to be otherworldly!
Yeah, it's almost as if Football was a team sport where players like to play well together.